Introduce a new netlink command to allow rdma event monitoring.
The rdma events supported now are IB device
registration/unregistration and net device attachment/detachment.
Example output of rdma monitor and the commands which trigger
the events:
$ rdma monitor
$ rmmod mlx5_ib
[UNREGISTER] dev 1 rocep8s0f1
[UNREGISTER] dev 0 rocep8s0f0
$ modprobe mlx5_ib
[REGISTER] dev 2 mlx5_0
[NETDEV_ATTACH] dev 2 mlx5_0 port 1 netdev 4 eth2
[REGISTER] dev 3 mlx5_1
[NETDEV_ATTACH] dev 3 mlx5_1 port 1 netdev 5 eth3
$ devlink dev eswitch set pci/0000:08:00.0 mode switchdev
[UNREGISTER] dev 2 rocep8s0f0
[REGISTER] dev 4 mlx5_0
[NETDEV_ATTACH] dev 4 mlx5_0 port 30 netdev 4 eth2
$ echo 4 > /sys/class/net/eth2/device/sriov_numvfs
[NETDEV_ATTACH] dev 4 rdmap8s0f0 port 2 netdev 7 eth4
[NETDEV_ATTACH] dev 4 rdmap8s0f0 port 3 netdev 8 eth5
[NETDEV_ATTACH] dev 4 rdmap8s0f0 port 4 netdev 9 eth6
[NETDEV_ATTACH] dev 4 rdmap8s0f0 port 5 netdev 10 eth7
[REGISTER] dev 5 mlx5_0
[NETDEV_ATTACH] dev 5 mlx5_0 port 1 netdev 11 eth8
[REGISTER] dev 6 mlx5_0
[NETDEV_ATTACH] dev 6 mlx5_0 port 1 netdev 12 eth9
[REGISTER] dev 7 mlx5_0
[NETDEV_ATTACH] dev 7 mlx5_0 port 1 netdev 13 eth10
[REGISTER] dev 8 mlx5_0
[NETDEV_ATTACH] dev 8 mlx5_0 port 1 netdev 14 eth11
$ echo 0 > /sys/class/net/eth2/device/sriov_numvfs
[UNREGISTER] dev 5 rocep8s0f0v0
[UNREGISTER] dev 6 rocep8s0f0v1
[UNREGISTER] dev 7 rocep8s0f0v2
[UNREGISTER] dev 8 rocep8s0f0v3
[NETDEV_DETACH] dev 4 rdmap8s0f0 port 2
[NETDEV_DETACH] dev 4 rdmap8s0f0 port 3
[NETDEV_DETACH] dev 4 rdmap8s0f0 port 4
[NETDEV_DETACH] dev 4 rdmap8s0f0 port 5